Since ﬂuoroquinolone (FQ) antibiotics are extensively used both in human and veterinary medicine their accumulation in the environment is causing increasing concern. The aim of the study was to isolate a microbial consortium resistant to oﬂ oxacin and norﬂ oxacin and able to biodegrade both antibiotics. Green compost was used as a source of microorganisms. The biodegradation efﬁ ciency was monitored by changes of antibiotics concentrations and toxicity. The microbial consortium was composed of two bacterial isolates: Klebsiella pneumoniae (K2) and Achromobacter sp. (K3) and two fungi Candida manassasensis (K1) and Trichosporon asahii (K4). All the isolates were characterized as highly resistant to both antibiotics – oﬂ oxacin and norﬂ oxacin. FQs were supplied individually into the culture medium in the presence of an easily degradable carbon source – glucose. Biodegradation of norﬂ oxacin was much faster than oﬂ oxacin biodegradation. During 20 days of the experiment, the norﬂ oxacin level decreased by more than 80%. Oﬂ oxacin was generally biodegraded thereafter at relatively slow biodegradation rate. After 28 days the oﬂ oxacin level decreased by 60%. Similarly, the toxicity of biodegraded antibiotics decreased 4-fold and 3.5-fold for norﬂ oxacin and oﬂ oxacin, respectively. The ability of the bacterial-fungal consortium to degrade antibiotics and reduce toxicity could help to reduce environmental pollution with these pharmaceutical.